In its various forms, graphene has garnered widespread interest for use in a number of applications, primarily due to its favorable combination of high electrical and thermal conductivity values, excellent in-plane mechanical strength, and unique optical and electronic properties. Perforated graphene has been suggested for use in filtration applications.
Formation of apertures or perforations in graphene by exposure to oxygen (O2) has been described in Liu et al, Nano Lett. 2008, Vol. 8, no. 7, pp. 1965-1970. As described therein, through apertures or holes in the 20 to 180 nm range were etched in single layer graphene using 350 Torr of oxygen in 1 atmosphere (atm) Argon at 500° C. for 2 hours. The graphene samples were reported to have been prepared by mechanical exfoliation of Kish graphite.
Another method is described in Kim et al. “Fabrication and Characterization of Large Area, Semiconducting Nanoperforated Graphene Materials,” Nano Letters 2010 Vol. 10, No. 4, Mar. 1, 2010, pp. 1125-1131. This reference describes use of a self-assembling polymer that creates a mask suitable for patterning using reactive ion etching (RIE). A P(S-blockMMA) block copolymer forms an array of PMMA columns that form vias for the RIE upon removal. It was reported that the graphene was formed by mechanical exfoliation.